High structure carbon blacks

ABSTRACT

Disclosed herein are high structured carbon blacks, methods of synthesis and treatment, and dispersions and inkjet ink formulations prepared therefrom. The carbon black can have the following properties: OAN≧170 mL/100 g; and STSA ranging from 160 to 220 m 2 /g. The carbon black can also have the following properties: OAN≧170 mL/100 g; and a ratio of STSA/BET surface area ranging from 0.7 to 1.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication Nos. 61/671,359, filed on Jul. 13, 2012, and 61/781,618,filed on Mar. 14, 2013, the disclosures of which are incorporated hereinby reference.

FIELD OF THE INVENTION

Disclosed herein are high structure carbon blacks, methods ofpreparation, and surface treatment thereof. Also disclosed aredispersions and inkjet ink compositions comprising such blacks.

BACKGROUND

There is a continual need for new carbon black materials to enhanceperformance in a number of applications. For example, in inkjet inkprinting, manufacturers seek improved optical density of the printedproduct, particularly as new paper types and printers are developed.

SUMMARY

One embodiment provides a carbon black having the following properties:

OAN≧170 mL/100 g; and

STSA ranging from 160 to 220 m²/g.

Another embodiment provides a carbon black having the followingproperties:

OAN≧170 mL/100 g; and

a ratio of STSA/BET ranging from 0.7 to 1.

Another embodiment provides a carbon black having the followingproperties:

OAN≧170 mL/100 g;

STSA ranging from 160 to 220 m²/g; and

BET surface area ranging from 190 to 275 m²/g.

Another embodiment provides a carbon black having the followingproperties:

OAN≧170 mL/100 g;

BET surface area ≧150 m²/g; and

COAN of at least 130 m²/g.

Another embodiment provides a method of oxidizing a pigment, comprisingadding ozone to an aqueous dispersion comprising the pigment whilemaintaining the aqueous dispersion at a pH of at least 8.5.

Another embodiment provides an ozone reactor assembly for oxidizing apigment having a circulated pathway, comprising:

a reservoir for containing and agitating a dispersion comprising apigment, the aqueous dispersion being in fluid communication with a pHprobe and a first pump for delivering a base to the dispersion;

a second pump in fluid communication with the reservoir for withdrawingand delivering the aqueous dispersion through a first hosing to aventuri tube, wherein the aqueous dispersion passes through aconstricted region of the venturi tube;

a source of ozone in gaseous communication with the venturi tube via aninlet at or upstream the constricted region, wherein the ozone contactsthe pigment while passing through the constricted region; and

a second hosing for carrying a mixture comprising ozone and the aqueousdispersion to the reservoir.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a cross-sectional schematic of a front end of a dual-stagecarbon black reactor; and

FIG. 2 is a schematic of an ozone reactor assembly.

DETAILED DESCRIPTION

Disclosed herein are high structure carbon blacks.

In one embodiment, the carbon blacks are channel blacks, furnace blacksand lamp blacks. In one embodiment, the carbon blacks disclosed hereinare furnace blacks. In one embodiment, the reactor for preparing furnacecarbon blacks black is a multi-stage reactor, such as those described inU.S. Pat. No. 7,829,057 or U.S. Pub. No. 2007/0104636, the disclosuresof which are incorporated herein by reference. As used herein, a“multi-stage reactor” is outfitted with two or more feedstock injectionlocations, with subsequent injection locations(s) being positioneddownstream a first injection location.

FIG. 1 is a cross-sectional schematic of the front end of a carbon blackreactor 2. Reactor 2 includes a combustion chamber 10 in which acombustion gas (liquid or gaseous fuel) is mixed with an oxidant(comprising, e.g., oxygen, air) and ignited by any method known in theart. The ignited gas flows through a frustoconical transition zone 11 toconverge the diameter to a generally tunnel-like zone 12 comprising anumber of tubular sections. Feedstock injection ports are positionedwithin front and end tubular sections 14A and 14B of zone 12, where endsection 14B is positioned downstream section 14A. Typically, more thanone injection inlet port is arranged circumferentially per each section14A and 14B. Between front and end sections 14A and 14B are one or morespacer transition tubings—FIG. 1 illustrates two spacer tubing sections16A and 16B, although one spacer tubing, or three or more spacer tubingscan be used depending on the desired carbon black property.

In the configuration of FIG. 1, fuel is ignited at combustion chamber 10and the resulting flow is directed to tunnel-like zone 12 where the fuelcontacts a first injection of feedstock injection at front tubingsection 14A. Subsequent flow through spacer tubings 16A and 16B allowsthe formation of seed carbon black particles, which then contact asecond charge of feedstock introduced at tubing section 14B. Thegas/carbon black particle mixture is then quenched at refractory 18. Thequenching is typically performed by a water spray at a quench location20, of which the distance from zone 12 can be varied. Thisconfiguration, such as the number of spacer tubings and dimensions,allows the production of high structure, highly branched carbon blackparticles via smaller seed or precursor carbon black particles.

One embodiment provides a carbon black having the following properties:

OAN≧170 mL/100 g; and

STSA ranging from 160 to 220 m²/g.

Another embodiment provides a carbon black having the followingproperties:

OAN≧170 mL/100 g; and

a ratio of STSA/BET ranging from 0.7 to 1.

In one embodiment, the carbon blacks are useful as pigments in, e.g.,inkjet ink compositions. In printing applications, there is a continuingneed to develop pigments and ink formulations that, when deposited on asubstrate such as paper, produce a printed product having high opticaldensity (O.D.). Often, high O.D. is associated with larger sizedparticles as these have a lesser tendency to penetrate the pores of thepaper. However, larger sized particles generally trend toward poorersedimentation performance, a disadvantageous property for long termstorage of inkjet ink formulations, e.g., in cartridges. It has beendiscovered that a combination of larger oil absorption number (OAN) andSTSA values (e.g., within a range of BET surface area values) canachieve the compromise between O.D. and sedimentation.

In one embodiment, the OAN ranges from 170 to 220 m²/g, e.g., from 170to 210 m²/g, from 180 to 220 m²/g, from 180 to 210 m²/g, from 190 to 220m²/g, or from 190 to 210 m²/g. OAN can be determined according toASTM-D2414. Without wishing to be bound by any theory, it has believedthat the disclosed OAN values can be a significant factor in achievinghigh optical density values.

In one embodiment, the STSA ranges from 160 to 220 m²/g, e.g., from 160to 210 m²/g, and in certain applications, the STSA ranges from 170 to220 m²/g, from 170 to 210 m²/g, from 180 to 220 m²/g, or from 180 to 220m²/g.

Another embodiment provides a carbon black having the followingproperties:

OAN≧170 mL/100 g; and

STSA ranging from 160 to 220 m²/g; and

BET surface area ranging from 190 to 275 m²/g.

Without wishing to be bound by any theory, it is believed that high STSAvalues and a certain range of BET surface areas achieve goodsedimentation performance, as indicated by lower sedimentation rates (%,as determined by the method of Example 6). In one embodiment, the BETsurface area ranges from 200 to 270 m²/g, such as a surface area rangingfrom 200 to 260 m²/g. The BET surface area can be determined accordingto ASTM-D6556.

Another embodiment involves the discovery that good printing andsedimentation performance can be achieved with carbon blacks having lowinternal volume, as determined by a ratio of STSA/BET ranging from 0.7to 1. A ratio of STSA/BET of 1 represents the limit when the carbonblack has substantially no internal porosity. In another embodiment,this range of STSA/BET ratios can be useful for applicationsincorporating conductive carbon blacks.

In one embodiment, the ratio of STSA/BET ranges from 0.7 to 0.9, or aratio of STSA/BET ranging from 0.7 to 0.8. In another embodiment, theratio of STSA/BET ranges from 0.8 to 1 or from 0.9 to 1. In oneembodiment, a ratio of STSA/BET ranging from 0.7 to 1 is achieved byminimizing the etching during carbon black formation. In one embodiment,the carbon black can have the STSA and/or BET values disclosed herein.

In one embodiment, the carbon black has a compressed OAN (COAN) of atleast 120 m²/g, e.g., at least 125 m²/g, at least 130 m²/g, at least 135m²/g, or a COAN ranging from 120-145 m²/g.

In one embodiment, the carbon black has a ratio of OAN/COAN ranging from1.30 to 1.50, e.g., from 1.30 to 1.45.

The carbon blacks disclosed herein can be useful in applications such asinkjet commercial printing (large or wide format printing, industrialprinting). In contrast to office printers, commercial printers haveoverall dimensions in the multi-foot or multi-meter range. Certain ofthese printers may employ ink cartridges having a stirrer assembly tostabilize the dispersion. In such cartridges, sedimentation rates of thesolids are not as significant a factor as in office printers.Accordingly, another embodiment provides high structure carbon blackshaving a high OAN and COAN values. In one embodiment, a carbon black hasthe following properties:

OAN≧170 mL/100 g;

BET surface area ≧150 m²/g; and

COAN of at least 130 m²/g.

In another embodiment, the carbon black has the following properties:

OAN≧170 mL/100 g;

BET surface area ≧150 m²/g; and

COAN ranging from 130 to 145 m²/g.

In one embodiment, the OAN ranges from 180 to 220 m²/g, from 180 to 210m²/g, from 190 to 220 m²/g, or from 190 to 210 m²/g. In one embodiment,the BET surface area ranges from 150 m²/g to 260 m²/g, from 150 m²/g to220 m²/g, from 160 m²/g to 260 m²/g, from 160 m²/g to 220 m²/g, from 170m²/g to 260 m²/g, from 170 m²/g to 220 m²/g, from 180 m²/g to 260 m²/g,or from 180 m²/g to 220 m²/g. In one embodiment, the OAN/COAN ratioranges from 1.30 to 1.50, e.g., from 1.30 to 1.45. In one embodiment,the STSA ranges from 130 m²/g to 220 m²/g, e.g., from 130 m²/g to 200m²/g.

Another embodiment relates to dispersions comprising the carbon blacksdisclosed herein. The dispersion can be aqueous or nonaqueous. In oneembodiment, the carbon blacks are treated to render themself-dispersible. For example, the carbon black can be an oxidizedcarbon black, e.g., having an oxygen content greater than or equal to3%, which can be determined by methods known in the art (e.g., elementalanalysis).

Generally, oxidized blacks feature a surface having ionic or ionizable,oxygen-containing groups such as one or more of phenols, lactones,carbonyls, carboxyls (e.g., carboxylic acids), anhydrides, ethers, andquinones. The extent of oxidation of carbon black can determine thesurface concentration of such ionic or ionizable groups. The carbonblacks disclosed herein can be oxidized by a variety of oxidizing agentsknown in the art. Exemplary oxidizing agents for carbon blacks includeoxygen gas, ozone, NO₂ (including mixtures of NO₂ and air), peroxidessuch as hydrogen peroxide, persulfates such as sodium, potassium, andammonium persulfate, hypohalites such as sodium hypochlorite, halites,halates, or perhalates (such as sodium chlorite, sodium chlorate, orsodium perchlorate), oxidizing acids such as nitric acid, and transitionmetal-containing oxidants such as permanganate salts, osmium tetroxide,chromium oxides, ceric ammonium nitrates, and mixtures thereof, e.g.,mixtures of gaseous oxidants such as oxygen and ozone. In oneembodiment, the carbon blacks disclosed herein are oxidized via ozoneoxidation.

In one embodiment, the carbon black is modified with at least oneorganic group. In one embodiment, the organic group is attached to thecarbon black, where an “attached” organic group can be distinguishedfrom an adsorbed group in that a soxhlet extraction for several hours(e.g., at least 4, 6, 8, 12, or 24 hours) will not remove the attachedgroup from the pigment (e.g., carbon black). In another embodiment, theorganic group is attached to the pigment (e.g., carbon black) if theorganic group cannot be removed after repeated washing (e.g., 2, 3, 4,5, or more washings) with a solvent or solvent mixture that can dissolvethe starting organic treating material but cannot disperse the treatedpigment. In yet another embodiment, “attached” refers to a bond such asa covalent bond, e.g., a pigment (e.g., carbon black) bonded orcovalently bonded to the organic group.

In one embodiment, the carbon black, whether as a raw material, anoxidized black, or a modified black (e.g., having an attached organicgroup), can be provided in dry form, such as a powder, pellet, granule,or cake. In one embodiment, “dry” refers to a material beingsubstantially free of water and optionally free of volatile material. Inone embodiment, dry forms include volatile material, such as about 50%or more of a volatile solvent.

In one embodiment, the carbon black is provided in the form having theconsistency of, for example, a paste or putty in a solid or semi-solidform (containing aqueous and/or nonaqueous materials/solvents), a slurryin which the carbon black is provided as an aqueous or nonaqueousdispersion, or as a bulk powder that can be a free flowing or a tackypowder.

The oxidized or modified carbon blacks disclosed herein can provideuseful properties when present in a dispersion. In one embodiment, thecarbon black in the dispersion has a mean volume (mV) ranging from 0.07to 0.18 μm, e.g., from 0.1 to 0.18 μm. In another embodiment, the carbonblack has a D10 ranging from 0.03 to 0.1 μm, e.g., from 0.05 to 0.1 μm,such as a D10 ranging from 0.06 to 0.1 μm, or from 0.07 to 0.1 μm. Inone embodiment, the carbon black has a D50 ranging from 0.07 to 0.16 μm,e.g., from 0.1 to 0.16 μm. In another embodiment, the carbon black has aD90 ranging from 0.15 to 0.25 μm, e.g., from 0.18 to 0.25 μm, such as aD90 ranging from 0.15 to 0.24 μm, or a D90 ranging from 0.18 to 0.24 μm.

The dispersion can be prepared by using any method known in the art. Forexample, the modified pigment in a dry form may be combined with theliquid vehicle with agitation to produce a stable dispersion. Anyequipment known in the art, such as a media or ball mill, or other highshear mixing equipment can be used, and various conventional millingmedia may also be used. Other methods for forming the dispersion will beknown to one skilled in the art.

In one embodiment, the dispersion comprises pigments such as the carbonblacks disclosed herein (e.g., oxidized carbon blacks or carbon blackshaving at least one attached organic group), and a liquid vehicle, e.g.,an aqueous or non-aqueous vehicle. In one embodiment, the vehiclecontains water, e.g., the vehicle comprises an aqueous solution. In oneembodiment, the aqueous solution contains greater than 50% by weightwater and can be, for example, water or mixtures of water with watermiscible solvents such as alcohols. In one embodiment, the amount ofpigment present in the dispersion can be varied but is typically in anamount ranging from 0.1% to 30%, e.g., from 1% to 25%, from 1% to 20%,from 3% to 20%, from 3% to 15%, based on the total weight of thedispersion.

Another embodiment provides inkjet ink compositions comprising thedispersions disclosed herein. The amount of modified pigment used in theinkjet ink composition can be varied but is typically in an amounteffective to provide the desired image quality (for example, opticaldensity) without detrimentally affecting the performance of the inkjetink. In one embodiment, the pigment such as the carbon blacks disclosedherein (e.g., oxidized carbon blacks or carbon blacks having at leastone attached organic group) is present in the inkjet ink composition inan amount ranging from 0.1% to 20%, e.g., from 1% to 20%, from 1% to10%, or from 3% to 8%, based on the total weight of the inkjet inkcomposition.

The inkjet ink composition can be formed with a minimum of additionalcomponents (additives and/or cosolvents) and processing steps. However,suitable additives may also be incorporated into these inkjet inkcompositions to impart a number of desired properties while maintainingthe stability of the compositions. For example, surfactants may be addedto further enhance the colloidal stability of the composition. Otheradditives are well known in the art and include humectants, biocides andfungicides, binders such as polymeric binders, pH control agents, dryingaccelerators, penetrants, and the like. The amount of a particularadditive will vary depending on a variety of factors but are generallypresent in an amount ranging between 0% and 40% based on the weight ofthe inkjet ink composition. Additionally, the inkjet ink compositions ofthe present invention may further incorporate dyes to modify colorbalance and adjust optical density. Such dyes include food dyes, FD&Cdyes, acid dyes, direct dyes, reactive dyes, derivatives ofphthalocyanine sulfonic acids, including copper phthalocyaninederivatives, sodium salts, ammonium salts, potassium salts, and lithiumsalts. Additional details on dispersions and the inkjet ink compositionsare provided below.

Ozone Oxidation

While the carbon blacks disclosed herein may be oxidized by any methodknown in the art (as described herein), another embodiment provides amethod of oxidizing a pigment, such as the carbon blacks disclosedherein. Alternatively, the disclosed ozone oxidation method is notlimited to the carbon blacks disclosed herein and can be used to oxidizeany pigment, e.g., other carbon blacks or organic pigments. Oneembodiment provides a method of oxidizing a pigment comprising addingozone to an aqueous dispersion comprising the pigment while maintainingthe aqueous dispersion at a pH of at least 8.5. In one embodiment, thepH is maintained at a value of at least 8.6, at least 8.7, at least 8.8,at least 8.9, at least 9.0, at least 9.1, at least 9.2, at least 9.3, atleast 9.4, or at least 9.5. In one embodiment, the pH of the mixture ismaintained at a value ranging from 8.5 to 10, 8.5 to 9.5, 8.6 to 10, 8.6to 9.5, 8.7 to 10, 8.7 to 9.5, 8.8 to 10, 8.8 to 9.5, 8.9 to 10, 8.9 to9.5, 9.0 to 10, or from 9.0 to 9.5. In one embodiment, the oxidizing andmaintaining are performed while the aqueous dispersion flows in acirculated pathway.

In one embodiment, the maintaining comprises adding a base to theaqueous dispersion when the pH level falls to a level below 8.5 (i.e.,less than 8.5), e.g., less than 8.6, less than 8.7, less than 8.8, lessthan 8.9, less than 9.0, less than 9.1, less than 9.2, less than 9.3,less than 9.4, or less than 9.5. For example, if it is desired that thepH level remain at a value of at least 8.5 or at least 9.0 (e.g., from9.0 to 10.0), the maintaining can be achieved with a pH probe and basepump in which the pH probe senses a drop in the pH level of the mixtureto below 8.5 (or below 9.0) as the oxidation proceeds. In response, thebase pump automatically adds a sufficient amount of base (e.g., NaOH,KOH) to cause the pH level to rise above 8.5 or above 9.0, or any of thevalues disclosed herein. In one embodiment, the aqueous dispersionpasses in a circulating flow through a venturi tube, and the addingcomprises introducing ozone to an inlet of the venturi tube, wherein theinlet is positioned at or upstream a constricted region of the venturitube.

One embodiment for achieving the ozone oxidization method comprises anozone reactor assembly having a circulated pathway. In one embodiment,the ozone reactor assembly comprises:

a reservoir for containing and agitating a dispersion comprising apigment, the aqueous dispersion being in fluid communication with a pHprobe and a first pump for delivering a base to the dispersion;

a second pump in fluid communication with the reservoir for withdrawingand delivering the aqueous dispersion through a first hosing to aventuri tube, wherein the aqueous dispersion passes through aconstricted region of the venturi tube;

a source of ozone in gaseous communication with the venturi tube via aninlet at or upstream the constricted region, wherein the ozone contactsthe pigment while passing through the constricted region; and

a second hosing for carrying a mixture comprising ozone and the aqueousdispersion to the reservoir.

FIG. 2 schematically illustrates an embodiment of an ozone reactorassembly. Reactor 50 comprises a reservoir 52 for containing a mixture54 comprising at least a pigment and solvent. In one embodiment, thismixture is a dispersion containing the carbon blacks disclosed herein,although other carbon black or organic pigments can be oxidized withthis assembly. The mixture can be agitated by any method known in theart, such as by stirring, rotating, vibrating, etc. FIG. 2 illustrates astirrer assembly 56. Component 58 is in fluid communication with themixture 54 and comprises a base pump, for introducing base to themixture 54 to maintain its basicity, and a pH probe for monitoring thepH of the solution. The base pump and pH probe can be provided asseparate components or as an integrated component. In one embodimentcomponent 58 monitors the pH level and maintains the pH of the mixtureto at least 8.5, or at least 9.0, or any of the values disclosed herein.

A fluid pump 60, in fluid communication with the mixture 54, draws themixture from reservoir 52, causing the mixture 54 to flow from reservoir52 through hosing 62 in a direction indicated by arrows 64. The mixture54 then enters a venturi tube 70 at inlet port 65. As schematicallyshown in FIG. 2, the diameter of venturi tube 70 decreases at section 72and minimizes at a constricted diameter region 74. The diameter decreaseof section 72 leading to and including the constricted diameter region74 is illustrated in conical fashion but may be achieved by a number ofconfigurations, e.g., stepwise or continually, in a linear, circular,coiled, serpentine, or tortuous pathway. Constricted diameter region 74connects to another inlet 69 through which ozone is introduced viahosing 68. The ozone can be generated by passing an oxygen gas fromsource 66 (e.g., a gas tank containing dried oxygen) to a coronagenerator 67. Corona generators typically generate an electricaldischarge capable of splitting oxygen molecules. The formed oxygenradicals can react with oxygen molecules to yield ozone. Other ozonegenerating systems can also be applied to reactor assembly 50. As theformed ozone enters the venturi tube at inlet 69 and into theconstricted diameter region 74, it contacts the pigment at the highestconcentrated pigment-containing region. Moreover, flow through theconstricted diameter region 74 maximizes the shearing forces, therebyoptimizing the reaction conditions between ozone and pigment. In oneembodiment, these advantages can also be realized if ozone is introducedupstream the constricted diameter region 74 where the resulting mixturesubsequently passes through this region for additional mixing andreaction.

The resulting mixture 54 (dispersion/ozone) eventually exits constricteddiameter region 74 via region 76 having an increased diameter inrelation to constricted diameter region 74. Upon exiting the venturitube 70, the mixture 54 travels through a second set of hosing 80 to bereintroduced back to the reservoir 52. With this assembly, the pigmentcan recirculate a number of times through the venturi tube 70 foradditional exposure to reactant ozone.

The carbon blacks disclosed herein can be subjected to a number ofalternative surface treatments and incorporated in various dispersionformulations, as described below.

Organic Groups

In one embodiment, the carbon black is a modified carbon black having atleast one attached organic group.

The organic group may be an aliphatic group, a cyclic organic group, oran organic compound having an aliphatic portion and a cyclic portion. Inone embodiment, the organic group is attached via a diazonium saltderived from a primary amine capable of forming, even transiently, adiazonium salt. Other methods of attachment are described below. Theorganic group may be substituted or unsubstituted, branched orunbranched. Aliphatic groups include, for example, groups derived fromalkanes, alkenes, alcohols, ethers, aldehydes, ketones, carboxylicacids, and carbohydrates. Cyclic organic groups include, but are notlimited to, alicyclic hydrocarbon groups (for example, cycloalkyls,cycloalkenyls), heterocyclic hydrocarbon groups (for example,pyrrolidinyl, pyrrolinyl, piperidinyl, morpholinyl, and the like), arylgroups (for example, phenyl, naphthyl, anthracenyl), and heteroarylgroups (imidazolyl, pyrazolyl, pyridinyl, thienyl, thiazolyl, furyl,indolyl, and triazolyl, such as 1,2,4-triazolyl and 1,2,3-triazolyl).

In one embodiment, the at least one attached organic group comprises atleast one ionic group, ionizable group, or mixtures of an ionic groupand an ionizable group. An ionic group can be either anionic or cationicand can be associated with a counterion of the opposite charge includinginorganic or organic counterions, such as Na⁺, K⁺, Li⁺, NH₄ ⁺, NR′₄ ⁺,acetate, NO₃ ⁻, SO₄ ²⁻, R′SO₃ ⁻, R′OSO₃ ⁻, OH⁻, or Cl⁻, where R′represents hydrogen or an organic group, such as a substituted orunsubstituted aryl or alkyl group. An ionizable group is one that iscapable of forming an ionic group in the medium of use. Anionic groupsare negatively charged ionic groups that can be generated from groupshaving ionizable substituents that can form anions (anionizable groups),such as acidic substituents. Cationic groups are positively chargedorganic ionic groups that can be generated from ionizable substituentsthat can form cations (cationizable groups), such as protonated amines.Specific examples of anionic groups include —COO⁻, —SO₃ ⁻, —OSO₃ ⁻,—HPO₃; —OPO₃ ²⁻, or —PO₃ ²⁻, and specific examples of an anionizablegroup can include —COOH, —SO₃H, —PO₃H₂, —R′SH, or —R′OH, where R′represents hydrogen or an organic group, such as a substituted orunsubstituted aryl or alkyl group. Also, specific examples of cationicor cationizable groups include alkyl or aryl amines, which can beprotonated in acidic media to form ammonium groups —NR′₂H⁺, where R′represent an organic group, such as a substituted or unsubstituted arylor alkyl groups. Organic ionic groups include those described in U.S.Pat. No. 5,698,016, the disclosure of which is incorporated herein byreference.

For example, the attached group may be an organic group such as abenzene carboxylic acid group (—C₆H₄—COOH group), a benzene dicarboxylicacid group, a benzene tricarboxylic acid group, a benzene sulfonic acidgroup (a —C₆H₄—SO₃H group), or salts thereof. In one embodiment, surfacemodification to introduce ionic or ionizable groups onto a pigmentsurface, such as chlorination and sulfonylation, may also be used.

In one embodiment, the organic group can be attached either directly(bonding to a native atom of the carbon black) or indirectly via anintermediary or spacer group. In one embodiment, the intermediary orspacer group is selected from substituted and unsubstituted C₁-C₁₂alkyl, C₅-C₂₀ aryl, C₆-C₂₄ alkyaryl and aralkyl, wherein “alkyl” can beoptionally interrupted by a group containing a heteroatom selected fromN, O, and S, and “aryl” includes ring carbon atoms optionally replacedby a group containing a heteroatom selected from N, O, and S. Typically,the attached group resides at the pigment surface.

The organic group can be substituted or unsubstituted. In oneembodiment, the organic group is substituted with at least onefunctional group selected from esters, amides, ethers, carboxyls, aryls,alkyls, halides, sulfonates, sulfates, phosphonates, phosphates,carboxylates, OR″, COR″, CO₂R″, OCOR″, CN, NR″₂, SO₂, CO, SO₃, SO₃H,OSO₂, OSO₃, SO₃NR″, R″NSO₂, NR″(COR″), NR″CO, CONR″₂, NO₂, NO₃, CONR″,NR″CO₂, O₂CNR″, NR″CONR″, S, NR″, SO₂C₂H₄, arylene as defined above,alkylene as defined above, wherein R″, which can be the same ordifferent, represents an organic group such as hydrogen, aryl, andalkyl, as defined herein.

Further examples of representative organic groups are described in U.S.Pat. Nos. 5,571,311; 5,630,868; 5,707,432, 5,955,232; 5,922,118;5,900,029; 5,895,522; 5,885,335; 5,851,280; 5,837,045; 5,713,988; and5,803,959; PCT Publication No. WO 96/18688; and PCT Publication No. WO96/18690, the disclosures of which are incorporated herein by reference.

In one embodiment, the organic group contains a 5-memberedheteroaromatic group comprising at least two ring heteroatoms, such asthose disclosed in PCT Pub. No. WO 2011/143533, the disclosure of whichis incorporated herein by reference. In one embodiment, the For example,the organic group can have formula (Ib) or (IIb):

For Ib, X can be O, N(R_(a)), or S; and R₁ can be H, C₁-C₁₀ alkyl,C₂-C₁₀ alkenyl, C₂-C₁₀ alkynyl, C₃-C₂₀ cycloalkyl, C₃-C₂₀ cycloalkenyl,C₁-C₂₀ heterocycloalkyl, C₁-C₂₀ heterocycloalkenyl, aryl, heteroaryl,halo, cyano, OR_(b), COOR_(b), OC(O)R_(b), C(O)R_(b), C(O)NR_(b)R_(c),SO₃R_(c), NR_(b)R_(c), or N⁺(R_(b)R_(c)R_(d))Y, in which each of R_(a),R_(b), R_(c), and R_(d), independently, can be H, C₁-C₁₀ alkyl, C₃-C₂₀cycloalkyl, C₁-C₂₀ heterocycloalkyl, aryl, or heteroaryl and Y can be ananion. In general, Y can be any suitable anion, such as chloride,bromide, iodide, sulfate, nitrate, phosphate, citrate, methanesulfonate,trifluoroacetate, acetate, malate, tosylate, tartrate, fumurate,glutamate, glucuronate, lactate, glutarate, or maleate. For Ilb, X is O,N(R_(a)), or S; and each of R₁ and R₂, independently, is H, C₁-C₁₀alkyl, C₂-C₁₀ alkenyl, C₂-C₁₀ alkynyl, C₃-C₂₀ cycloalkyl, C₃-C₂₀cycloalkenyl, C₁-C₂₀ heterocycloalkyl, C₁-C₂₀ heterocycloalkenyl, aryl,heteroaryl, halo, cyano, OR_(b), COOR_(b), OC(O)R_(b), C(O)R_(b),C(O)NR_(b)R_(c), SO₃R_(c), NR_(b)R_(c), or N⁺(R_(b)R_(c)R_(d))Y, each ofR_(a), R_(b), R_(c), and R_(d), independently, being H, C₁-C₁₀ alkyl,C₃-C₂₀ cycloalkyl, C₁-C₂₀ heterocycloalkyl, aryl, or heteroaryl and Ybeing an anion; provided that at least one of R₁ and R₂ is not H.

In one embodiment, the at least one organic group comprises the formula—[R(A)]-, wherein:

R is attached to the carbon black and is selected from arylene,heteroarylene, and alkylene, and

A is selected from carboxylic acids, sulfonic acids, phosphonic acids,hydroxyls, amines, and esters, amides, and salts thereof.

In another embodiment, the at least one organic group comprises theformula —[R(A)]-, wherein:

R is attached to the carbon black and is selected from arylene,heteroarylene, and alkylene, and

A is selected from hydrogen, alkyls, aryls, heteroaryls, alkylene oxides(e.g., ethylene or propylene oxide), carboxylic acid esters, andglycols.

In another embodiment, the at least one organic group comprises theformula —[R(A)]-, wherein:

R is attached to the carbon black and is selected from arylene,heteroarylene, and alkylene, and

A is selected from polymers.

The arylene, heteroarylene, and alkylene can be unsubstituted orsubstituted, e.g., with one or more of the functional groups listedabove. Exemplary arylenes include phenylene, naphthylene, andbiphenylene, and exemplary heteroarylenes include phenylene,naphthylene, and biphenylene having a ring carbon substituted with oneor more oxygen or nitrogen atoms. In one embodiment, the arylene is aC₅-C₂₀ arylene. Heteroarylenes can be an arylene as defined herein whichone or more ring carbon atoms is replaced with a heteroatom, e.g., N, O,and S. The heteroatom can be bonded to other groups in addition to beinga ring atom. Exemplary arylenes include phenyl, naphthyl, anthracenyl,phenanthrenyl, biphenyl, and exemplary heteroarylenes include pyridinyl,imidazolyl, pyrazolyl, thienyl, thiazolyl, furyl, triazinyl, indolyl,benzothiadiazolyl, and benzothiazolyl. Alkylenes may be branched orunbranched. The alkylene may be a C₁-C₁₂ alkylene such as methylene,ethylene, propylene, or butylene, optionally interrupted by aheteroatom.

In one embodiment, R is a substituted R and comprises an arylene,heteroarylene, and alkylene substituted with at least a spacer groupthat is bonded to A. In one embodiment, a substituted R comprises R′—Sp,wherein R′ is selected from arylene, heteroarylene, and alkylene, asdefined above, and Sp is a spacer selected from the functional groupslisted above capable of bonding to both R′ and A. In another embodiment,Sp is selected from —CO₂—, —O₂C—, —CO—, —OSO₂—, —SO₃—, —SO₂—,—SO₂C₂H₄—O—, —SO₂C₂H₄S—, —SO₂C₂H₄NR″—, —O—, —S—, —NR″—, —NR″CO—,—CONR″—, —NR″CO₂—, —O₂CNR″—, —NR″CONR″—, —N(COR″)CO—, —CON(COR″)—,—NR″COCH(CH₂CO₂R″)— and cyclic imides therefrom, —NR″COCH₂CH(CO₂R″)— andcyclic imides therefrom, —CH(CH₂CO₂R″)CONR″—, and cyclic imidestherefrom, —CH(CO₂R″)CH₂CONR″ and cyclic imides therefrom, (includingphthalimide and maleimides of these), sulfonamide groups (including—SO₂NR″— and —NR″SO₂-groups), arylene groups, alkylene groups. R″, whichcan be the same or different, is defined as above, or representshydrogen or an organic group such as a substituted or unsubstituted arylor alkyl group, e.g., C₅-C₂₀ aryl groups, and substituted andunsubstituted C₁-C₆ alkyl groups. In one embodiment, Sp is selected from—CO₂—, —O₂C—, —O—, —NR″—, —NR″CO—, —CONR″—, —SO₂NR″—, —SO₂CH₂CH₂NR″—,—SO₂CH₂CH₂O—, or —SO₂CH₂CH₂S— wherein R″ is defined as above, e.g.,selected from H and C₁-C₆ alkyl groups.

In another embodiment, Sp is derived from a compound having a reactivegroup selected from a carboxylic acid or ester, an acid chloride, asulfonyl chloride, an acyl azide, an isocyanate, a ketone, an aldehyde,an anhydride, an amide, an imide, an imine, an α,β-unsaturated ketone,aldehyde, or sulfone, an alkyl halide, an epoxide, an alkyl sulfonate orsulfate such as a (2-sulfatoethyl)-sulfone group, an amine, a hydrazine,an alcohol, a thiol, a hydrazide, an oxime, a triazene, a carbanion, anaromatic compound, salts or derivatives thereof, or any combinationthereof. Examples of such compounds include include amino-functionalizedaromatic compounds, such as 4-aminobenzyl amine (4-ABA), 3-aminobenzylamine (3-ABA), 2-aminobenzyl amine (2-ABA), 2-aminophenyl ethylamine,4-aminophenyl-(2-sulfatoethyl)-sulphone, (APSES), p-aminobenzoic acid(PABA), 4-aminophthalic acid (4-APA), and5-aminobenzene-1,2,3-tricarboxylic acid.

In one embodiment, the at least one organic group is capable of bindingcalcium (e.g., having defined calcium index values), including thoseorganic groups described in PCT Pub. No. WO 2007/053564, the disclosureof which is incorporated herein by reference. For example, the organicgroup comprises at least one geminal bisphosphonic acid group, partialesters thereof, or salts thereof, e.g., a group having the formula—CQ(PO₃H₂)₂, partial esters thereof, or salts thereof, wherein Q isbonded to the geminal position and may be H, R, OR, SR, or NR₂ whereinR″, which can be the same or different, is defined as above, or can beH, a C₁-C₁₈ saturated or unsaturated, branched or unbranched alkylgroup, a C₁-C₁₈ saturated or unsaturated, branched or unbranched acylgroup, an aralkyl group, an alkaryl group, or an aryl group. Inaddition, U.S. Pat. Nos. 5,672,198, 5,922,118, 6,042,643, and 6,641,656disclose modified pigments having various attached groups, includingphosphonic acid groups, the disclosures of which are incorporated hereinby reference.

Other organic groups capable of binding calcium include: at least onehydroxamic acid group or salt thereof (e.g., at least one group havingthe formula —N(OH)—CO— or a salt thereof); at least one heteroaryl grouphaving at least one OH group or salt thereof (e.g., anitrogen-containing heteroaryl group, such as a pyridinyl group or aquinolinyl group, and the organic group is a hydroxy pyridinyl group ora hydroxy quinolinyl group, in which the hydroxy group is at a positionon the heteroaryl group such that it is geometrically close to theheteroatom, such as ortho to the heteroatom; or a heteroaryl having twoOH groups in positions ortho to each other); at least one phosphonicacid group or salt thereof and at least one second ionic, ionizable orbasic group (a basic group is a Lewis base, such as an OH group or anamino group that can be geminal to the phosphonic acid group); at leastone heteroaryl group having at least one carboxylic acid group or saltthereof (e.g., at least two or three carboxylic acid groups, such as atleast two carboxylic acid groups that are ortho or meta to each other);an aryl group having at least one nitroso group and at least one OHgroup (e.g., ortho to each other), or a salt thereof; an azoarene grouphaving at least two OH groups, at least two NH₂ groups, or at least oneOH group and at least one NH₂ group (e.g., at least two OH groups, atleast two NH₂ groups, or at least one OH group and at least one NH₂group) and has the formula Ar¹—N═N—Ar², wherein Ar¹ and Ar², which canbe the same or different, are an arylene group or an aryl group and atleast one of Ar¹ or Ar² is an arylene group (e.g., the OH and/or NH₂groups are located at positions ortho to the azo group). Other groupsare disclosed in WO 2007/053564.

In one embodiment, the attached organic group comprises a polymer. Inone embodiment, the polymer comprises at least one non-ionic group.Examples include alkylene oxide groups of from about 1 to about 12carbons and polyols, such as a —CH₂—CH₂—O— group, a —CH(CH₃)—CH₂—O—group, a —CH₂—CH(CH₃)—O— group, a —CH₂CH₂CH₂—O— group, or combinationsthereof. These non-ionic groups may further comprise at least one ionicor ionizable group as disclosed herein.

The attached polymers, which can be homopolymers or copolymers, can alsobe derived from monomers selected from acrylic and methacrylic acid,acrylate esters, methacrylate esters, acrylamides and methacrylamides,acrylonitriles, cyanoacrylate esters, maleate and fumarate diesters,vinyl pyridines, vinyl N-alkylpyrroles, vinyl acetate, vinyl oxazoles,vinyl thiazoles, vinyl pyrimidines, vinyl imidazoles, vinyl ketones,vinyl ethers, and styrenes. Vinyl ethers include those that can beprepared by cationic polymerization, such as those having the generalstructure CH₂═CH(OR), wherein R is an alkyl, aralkyl, alkaryl, or arylgroup or is a group comprising one or more alkylene oxide groups. Vinylketones include those in which the β-carbon atom of the alkyl group doesnot bear a hydrogen atom, such as vinyl ketones in which both β-carbonsbear a C₁-C₄ alkyl group, halogen, etc. or a vinyl phenyl ketone inwhich the phenyl group may be substituted with from 1 to 5 C₁-C₆ alkylgroups and/or halogen atoms. Styrenes include those in which the vinylgroup is substituted with a C₁-C₆ alkyl group, such as at the a-carbonatom, and/or those in which the phenyl group is substituted with from 1to 5 substituents including a C₁-C₆ alkyl, alkenyl (including vinyl), oralkynyl (including acetylenyl) group, a phenyl group, a haloalkyl group,and functional groups such as C₁-C₆ alkoxy, halogen, nitro, carboxy,sulfonate, C₁-C₆ alkoxycarbonyl, hydroxy (including those protected witha C₁-C₆ acyl group), and cyano groups. Specific examples include methylacrylate (MA), methyl methacrylate (MMA), ethyl acrylate (EA), ethylmethacrylate (EMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA),acrylonitrile (AN), methacrylonitrile, styrene, and derivatives thereof.

The polymer can be prepared by the cationic or anionic polymerization ofone or more polymerizable monomers. For example, polyvinyl ethers can beprepared by cationic polymerization of monomers, such as those havingthe general structure CH₂═CH(OR), wherein R is an alkyl, aralkyl,alkaryl, or aryl group or is a group comprising one or more alkyleneoxide groups. Other cationically or anionically polymerizable monomerscan also be included.

The polymer can also be prepared by polycondensation techniques. Forexample, the polymer may be a polyester or a polyurethane having afunctional group described above. For polyurethanes, examples ofsuitable methods include a solution method which comprises preparing anisocyanate-terminated prepolymer in a low boiling solvent (such asacetone) unreactive with an isocyanate group, introducing a hydrophilicgroup such as diamine or polyol therein, effecting phase change bydiluting with water, and distilling off a solvent to obtain apolyurethane dispersion. Another suitable method comprises preparing anisocyanate group-terminated prepolymer having a hydrophilic groupintroduced, dispersing in water, and extending a chain with an amine.

Polyurethanes may be prepared by the prepolymer method, and apolyhydroxy compound having a low molecular weight may be used at thattime. Examples of the polyhydroxy compound having a low molecular weightinclude polyester diols such as glycol and alkylene oxide, a trihydricalcohol such as glycerin, trimethylolethane and trimethylolpropane.

In one embodiment, the polymer has a low acid number. In one embodiment,the polymer may be an acidic group containing polymer having an acidnumber of less than or equal to about 200, such as less than or equal toabout 150, less than or equal to about 110, or less than or equal toabout 100. In another embodiment, the acid number of the polymer isgreater than or equal to about 30. Thus, the polymer may be an acidicgroup containing polymer having an acid number of from about 30 to about200, such as from about 30 to about 110, from about 110 to about 150, orfrom about 150 to about 200.

In one embodiment, the carbon black is modified with at least oneorganic group via a diazonium treatment as detailed, for instance, inthe following patents: U.S. Pat. Nos. 5,554,739; 5,630,868; 5,672,198;5,707,432; 5,851,280; 5,885,335; 5,895,522; 5,900,029; 5,922,118;6,042,643; 6,534,569; 6,398,858 and 6,494,943 (high shear conditions)6,372,820; 6,368,239; 6,350,519; 6,337,358; 6,103,380; 7,173,078;7,056,962; 6,942,724; 6,929,889; 6,911,073; 6,478,863; 6,472,471; and WO2011/143533, the disclosures of which are incorporated herein byreference. In one embodiment, the attachment is provided via a diazoniumreaction where the at least one organic group has a diazonium saltsubstituent. In another embodiment, the direct attachment can be formedby using the diazonium and stable free radical methods described, forinstance, in U.S. Pat. Nos. 6,068,688; 6,337,358; 6,368,239; 6,551,393;6,852,158, the disclosures of which are incorporated herein byreference, which makes use of reacting at least one radical with atleast one particle, wherein a radical is generated from the interactionof at least one transition metal compound with at least oneorgano-halide compound in the presence of one or more particles capableof radical capture, and the like. In yet another embodiment, the atleast one carbon black can be modified (e.g., to attach functionalgroups) by using the methods of U.S. Pat. Nos. 5,837,045, 6,660,075 andWO 2009/048564 (reaction with organic compounds containing a C—C doublebond or triple bond activated by at least one substituent) or U.S. Pub.No. 2004/0171725, U.S. Pat. Nos. 6,664,312, 6,831,194 (reaction withanhydride component), U.S. Pat. No. 6,936,097, U.S. Pub. Nos.2001/0036994, 2003/0101901 (reaction with organic groups having —N═N—N—group), Canadian Patent No. 2,351,162, European Patent No. 1 394 221,and PCT Publication Nos. WO 01/51566 (reaction between at least oneelectrophile and at least one nucleophile), WO 04/63289, WO 2010/141071(reaction with H2N-A-Y where A is a heteroatom), and WO 99/23174, thedisclosures of which are incorporated herein by reference.

In one embodiment, the carbon black is attached to the organic group viaan —O—C— bond, wherein the —O—C— bond forms one or more of phenolate,naphtholate, ester, and ether linkages wherein the carbon atom of the—O—C— bond, and substituents thereof, are not native to the carbon blackprior to modification. In one embodiment, and carbon black is attachedto the organic group via phenolate or naphtholate linkages in which thearomatic groups of the phenolate or naptholate are native to the carbonblack. In one embodiment, these linkages can be achieved via a Mitsunobureaction, as disclosed in PCT App. No. PCT/US2013/39381, in which afirst reactant comprising a protonated nucleophile having a pKa<15 isreacted with a second reactant comprising a hydroxyl-containing organicgroup. The carbon black can be attached to either the first or secondreactant.

Other methods to prepare modified pigments, including those havingattached polymeric groups, have also been described in, for example, PCTPublication No. WO 01/51566, which discloses methods of making amodified pigment by reacting a first chemical group and a secondchemical group to form a pigment having attached a third chemical group.PCT Pub. No. WO 2007/053563 discloses modified colorants having attachedat least one polymeric group comprising a polymer having at least onefunctional group having defined calcium index values. Specificembodiments of the organic groups are described, including organicgroups comprising at least one geminal bisphosphonic acid group, partialesters thereof, or salts thereof.

Other methods for the preparation of polymer modified pigment productshave also been developed. For example, U.S. Pat. Nos. 7,056,962,6,478,863, 6,432,194, 6,336,965, U.S. Pub. No. 2006/0189717, and PCTPub. No. WO 2008/091653 the disclosures of which are incorporated hereinby reference, describe methods for attaching polymers to pigmentsthrough the use of a diazonium salt. U.S. Pat. Nos. 7,173,078,6,916,367, 6,911,073, 6,723,783, 6,699,319, 6,472,471, and 6,110,994,the disclosures of which are incorporated herein by reference, disclosemethods of preparing a polymer modified pigment by reacting polymer anda pigment having an attached reactive group. Modified pigments havingattached polymeric groups have also been disclosed in U.S. Pub. No.2008/0177003, the disclosure of which is incorporated herein byreference, utilizes a polymer in the form of a melt.

The polymer modified pigments may also be prepared by polymerization ofmonomers from a pigment. For example, the polymer modified pigments maybe prepared by radical polymerization, controlled polymerizationmethods, such as atom transfer radical polymerization (ATRP), stablefree radical (SFR) polymerization, and reversible addition-fragmentationchain transfer polymerization (RAFT), ionic polymerizations (anionic orcationic) such as group transfer polymerization (GTP), and condensationpolymerization. Also, the polymer modified pigments may be preparedusing the methods described in, for example, U.S. Pat. Nos. 6,372,820;6,350,519; 6,551,393; or 6,368,239 or in PCT Pub. Nos. 2006/086599 and2006/086660, the disclosures of which are incorporated herein byreference. For modified pigments comprising the pigment coated by thepolymer, these modified pigments can be prepared using any method knownin the art, such as those described in U.S. Pat. Nos. 5,085,698,5,998,501, 6,074,467, 6,852,777, and 7,074,843, and International PatentPublication Nos. WO 2004/111,140, WO 2005/061087, and WO 2006/064193,the disclosures of which are incorporated herein by reference.

The surface grafting carbon black with polymers and prepolymers isdescribed in N. Tsubokawa, in Prog. Polym. Sci., 17, 417, 1992, and J.Polym. Sci. Polym. Chem. Ed. Vol. 20, 1943-1946 (1982), the disclosuresof which are incorporated herein by reference. Polymers having terminalhydroxyl or amino groups can be grafted onto surface carboxyl groups ofthe carbon black, as disclosed in N. Tsubokawa in Reactive & FunctionalPolymers 27 (1995) 75-81.

The modified pigments having attached at least one polymeric group mayfurther comprise a second organic group, which is different from thepolymeric groups described above. These include, for example, the groupsdescribed in U.S. Pat. No. 5,630,868, the disclosure of which isincorporated herein by reference. For example, the modified pigment mayfurther comprise a second attached organic group that may comprise atleast one ionic group, at least one ionizable group, or a mixturethereof. Preferably the ionic or ionizable group is an anionic oranionizable group. Any of the ionic or ionizable groups, particularlythe anionic or anionizable groups, described above regarding the pigmentof the modified pigment of the present invention may be the secondorganic group. Furthermore, the second organic group may be a polymericgroup comprising a polymer. Any of the polymeric groups described abovecan also be used as the second attached organic group.

The amount of attached organic groups can be varied, depending on thedesired use of the modified carbon black and the type of attached group.For example, the total amount of organic group may be from about 0.01 toabout 10.0 micromoles of groups/m² surface area of pigment, as measuredby nitrogen adsorption (BET method), including from about 0.5 to about5.0 micromoles/m², from about 1 to about 3 micromoles/m², or from about2 to about 2.5 micromoles/m². Additional attached organic groups, whichdiffer from those described for the various embodiments of the presentinvention, may also be present.

Dispersions and Inkjet Ink Compositions

Dispersing agents (surfactants and/or dispersants) may be added tofurther enhance the colloidal stability of the composition or to changethe interaction of the ink with either the printing substrate, such asprinting paper, or with the ink printhead. Various anionic, cationic andnonionic dispersing agents can be used in conjunction with the inkcomposition of the present invention, and these may be used neat or as awater solution.

Representative examples of anionic dispersants or surfactants include,but are not limited to, higher fatty acid salts, higheralkyldicarboxylates, sulfuric acid ester salts of higher alcohols,higher alkyl-sulfonates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, naphthalene sulfonates (Na, K, Li, Ca, etc.), formalinpolycondensates, condensates between higher fatty acids and amino acids,dialkylsulfosuccinic acid ester salts, alkylsulfosuccinates,naphthenates, alkylether carboxylates, acylated peptides, a-olefinsulfonates, N-acrylmethyl taurine, alkylether sulfonates, secondaryhigher alcohol ethoxysulfates, polyoxyethylene alkylphenylethersulfates, monoglycylsulfates, alkylether phosphates and alkylphosphates, alkyl phosphonates and bisphosphonates, includedhydroxylated or aminated derivatives. For example, polymers andcopolymers of styrene sulfonate salts, unsubstituted and substitutednaphthalene sulfonate salts (e.g. alkyl or alkoxy substitutednaphthalene derivatives), aldehyde derivatives (such as unsubstitutedalkyl aldehyde derivatives including formaldehyde, acetaldehyde,propylaldehyde, and the like), maleic acid salts, and mixtures thereofmay be used as the anionic dispersing aids. Salts include, for example,Na⁺, Li⁺, K⁺, Cs⁺, Rb⁺, and substituted and unsubstituted ammoniumcations. Representative examples of cationic surfactants includealiphatic amines, quaternary ammonium salts, sulfonium salts,phosphonium salts and the like.

Representative examples of nonionic dispersants or surfactants that canbe used in ink jet inks of the present invention include fluorinederivatives, silicone derivatives, acrylic acid copolymers,polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether,polyoxyethylene secondary alcohol ether, polyoxyethylene styrol ether,ethoxylated acetylenic diols, polyoxyethylene lanolin derivatives,ethylene oxide derivatives of alkylphenol formalin condensates,polyoxyethylene polyoxypropylene block polymers, fatty acid esters ofpolyoxyethylene polyoxypropylene alkylether polyoxyethylene compounds,ethylene glycol fatty acid esters of polyethylene oxide condensationtype, fatty acid monoglycerides, fatty acid esters of polyglycerol,fatty acid esters of propylene glycol, cane sugar fatty acid esters,fatty acid alkanol amides, polyoxyethylene fatty acid amides andpolyoxyethylene alkylamine oxides. For example, ethoxylated monoalkyl ordialkyl phenols may be used. These nonionic surfactants or dispersantscan be used alone or in combination with the aforementioned anionic andcationic dispersants.

The dispersing agents may also be a natural polymer or a syntheticpolymer dispersant. Specific examples of natural polymer dispersantsinclude proteins such as glue, gelatin, casein and albumin; naturalrubbers such as gum arabic and tragacanth gum; glucosides such assaponin; alginic acid, and alginic acid derivatives such aspropyleneglycol alginate, triethanolamine alginate, and ammoniumalginate; and cellulose derivatives such as methyl cellulose,carboxymethyl cellulose, hydroxyethyl cellulose and ethylhydroxycellulose. Specific examples of polymeric dispersants, includingsynthetic polymeric dispersants, include polyvinyl alcohols,polyvinylpyrrolidones, acrylic or methacrylic resins (often written as“(meth)acrylic”) such as poly(meth)acrylic acid, acrylicacid-(meth)acrylonitrile copolymers, potassium(meth)acrylate-(meth)acrylonitrile copolymers, vinylacetate-(meth)acrylate ester copolymers and (meth)acrylicacid-(meth)acrylate ester copolymers; styrene-acrylic or methacrylicresins such as styrene-(meth)acrylic acid copolymers,styrene-(meth)acrylic acid-(meth)acrylate ester copolymers,styrene-a-methylstyrene-(meth)acrylic acid copolymers,styrene-a-methylstyrene-(meth)acrylic acid-(meth)acrylate estercopolymers; styrene-maleic acid copolymers; styrene-maleic anhydridecopolymers, vinyl naphthalene-acrylic or methacrylic acid copolymers;vinyl naphthalene-maleic acid copolymers; and vinyl acetate copolymerssuch as vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinylethylene copolymers, vinyl acetate-maleate ester copolymers, vinylacetate-crotonic acid copolymer and vinyl acetate-acrylic acidcopolymer; and salts thereof.

Humectants and water soluble organic compounds may also be added to theinkjet ink composition of the present invention, particularly for thepurpose of preventing clogging of the nozzle as well as for providingpaper penetration (penetrants), improved drying (drying accelerators),and anti-cockling properties. Specific examples of humectants and otherwater soluble compounds that may be used include low molecular-weightglycols such as ethylene glycol, diethylene glycol, triethylene glycol,tetraethylene glycol and dipropylene glycol; diols containing from about2 to about 40 carbon atoms, such as 1,3-pentanediol, 1,4-butanediol,1,5-pentanediol, 1,4-pentanediol, 1,6-hexanediol, 1,5-hexanediol,2,6-hexanediol, neopentylglycol (2,2-dimethyl-1,3-propanediol),1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,1,2,6-hexanetriol, poly(ethylene-co-propylene) glycol, and the like, aswell as their reaction products with alkylene oxides, including ethyleneoxides, including ethylene oxide and propylene oxide; triol derivativescontaining from about 3 to about 40 carbon atoms, including glycerine,trimethylolpropane, 1,3,5-pentanetriol, 1,2,6-hexanetriol, and the likeas well as their reaction products with alkylene oxides, includingethylene oxide, propylene oxide, and mixtures thereof; neopentylglycol,(2,2-dimethyl-1,3-propanediol), and the like, as well as their reactionproducts with alkylene oxides, including ethylene oxide and propyleneoxide in any desirable molar ratio to form materials with a wide rangeof molecular weights; thiodiglycol; pentaerythritol and lower alcoholssuch as ethanol, propanol, iso-propyl alcohol, n-butyl alcohol,sec-butyl alcohol, and tert-butyl alcohol, 2-propyn-1-ol (propargylalcohol), 2-buten-1-ol, 3-buten-2-ol, 3-butyn-2-ol, and cyclopropanol;amides such as dimethyl formaldehyde and dimethyl acetamide; ketones orketoalcohols such as acetone and diacetone alcohol; ethers such astetrahydrofuran and dioxane; cellosolves such as ethylene glycolmonomethyl ether and ethylene glycol monoethyl ether, triethylene glycolmonomethyl (or monoethyl) ether; carbitols such as diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, and diethyleneglycol monobutyl ether; lactams such as 2-pyrrolidone,N-methyl-2-pyrrolidone and 8-caprolactam; urea and urea derivatives;inner salts such as betaine, and the like; thio (sulfur) derivatives ofthe aforementioned materials including 1-butanethiol; t-butanethiol1-methyl-1-propanethiol, 2-methyl-1-propanethiol;2-methyl-2-propanethiol; thiocyclopropanol, thioethyleneglycol,thiodiethyleneglycol, trithio- or dithio-diethyleneglycol, and the like;hydroxyamide derivatives, including acetylethanolamine,acetylpropanolamine, propylcarboxyethanolamine, propylcarboxypropanolamine, and the like; reaction products of the aforementionedmaterials with alkylene oxides; and mixtures thereof. Additionalexamples include saccharides such as maltitol, sorbitol, gluconolactoneand maltose; polyhydric alcohols such as trimethylol propane andtrimethylol ethane; N-methyl-2-pyrrolidone;1,3-dimethyl-2-imidazolidinone; sulfoxide derivatives containing fromabout 2 to about 40 carbon atoms, including dialkylsulfides (symmetricand asymmetric sulfoxides) such as dimethylsulfoxide,methylethylsulfoxide, alkylphenyl sulfoxides, and the like; and sulfonederivatives (symmetric and asymmetric sulfones) containing from about 2to about 40 carbon atoms, such as dimethylsulfone, methylethylsulfone,sulfolane (tetramethylenesulfone, a cyclic sulfone), dialkyl sulfones,alkyl phenyl sulfones, dimethylsulfone, methylethylsulfone,diethylsulfone, ethylpropylsulfone, methylphenylsulfone,methylsulfolane, dimethylsulfolane, and the like. Such materials may beused alone or in combination.

Biocides and/or fungicides may also be added to the inkjet inkcomposition of the present invention. Biocides are important inpreventing bacterial growth since bacteria are often larger than inknozzles and can cause clogging as well as other printing problems.Examples of useful biocides include, but are not limited to, benzoate orsorbate salts, and isothiazolinones.

In one embodiment, the inkjet ink composition comprises a cosolvent. Inone embodiment, the cosolvent is soluble or miscible in water atconcentrations of at least 10% by weight and is also chemically stableto aqueous hydrolysis conditions (e.g., reaction with water under heataging conditions, including, for example, the hydrolysis of esters andlactones). In one embodiment, the cosolvent has a dielectric constantbelow that of water, such as a dielectric constant ranging from about 10to about 78 at 20° C. Examples of suitable cosolvents include lowmolecular-weight glycols (such as ethylene glycol, diethylene glycol,triethylene glycol, tetraethylene glycol, dipropylene glycol, ethyleneglycol monomethyl ether, ethylene glycol monoethyl ether, triethyleneglycol monomethyl or monoethyl ether, diethylene glycol monomethylether, diethylene glycol monoethyl ether, diethylene glycol monobutylether, and tetraethylene glycol monobutyl ether); alcohols (such asethanol, propanol, iso-propyl alcohol, n-butyl alcohol, sec-butylalcohol, and tert-butyl alcohol, 2-propyn-1-ol (propargyl alcohol),2-buten-1-ol, 3-buten-2-ol, 3-butyn-2-ol, and cyclopropanol); diolscontaining from about 2 to about 40 carbon atoms (such as1,3-pentanediol, 1,4-butanediol, 1,5-pentanediol, 1,4-pentanediol,1,6-hexanediol, 1,5-hexanediol, 2,6-hexanediol, neopentylglycol(2,2-dimethyl-1,3-propanediol), 1,3-propanediol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, andpoly(ethylene-co-propylene) glycol, as well as their reaction productswith alkylene oxides, including ethylene oxides, including ethyleneoxide and propylene oxide); triols containing from about 3 to about 40carbon atoms (such as glycerine (glycerol), trimethylolethane,trimethylolpropane, 1,3,5-pentanetriol, 1,2,6-hexanetriol, and the likeas well as their reaction products with alkylene oxides, includingethylene oxide, propylene oxide, and mixtures thereof); polyols (such aspentaerythritol); amides (such as dimethyl formaldehyde and dimethylacetamide); ketones or ketoalcohols (such as acetone and diacetonealcohol); ethers (such as tetrahydrofuran and dioxane); lactams (such as2-pyrrolidone, N-methyl-2-pyrrolidone, and ∈-caprolactam); ureas or ureaderivatives (such as di-(2-hydroxyethyl)-5,5,-dimethyl hydantoin(dantacol) and 1,3-dimethyl-2-imidazolidinone); inner salts (such asbetaine); and hydroxyamide derivatives (such as acetylethanolamine,acetylpropanolamine, propylcarboxyethanolamine, and propylcarboxypropanolamine, as well as their reaction products with alkylene oxides).Additional examples include saccharides (such as maltitol, sorbitol,gluconolactone and maltose); sulfoxide derivatives (symmetric andasymmetric) containing from about 2 to about 40 carbon atoms (such asdimethylsulfoxide, methylethylsulfoxide, and alkylphenyl sulfoxides);and sulfone derivatives (symmetric and asymmetric) containing from about2 to about 40 carbon atoms (such as dimethylsulfone, methylethylsulfone,sulfolane (tetramethylenesulfone, a cyclic sulfone), dialkyl sulfones,alkyl phenyl sulfones, dimethylsulfone, methylethylsulfone,diethylsulfone, ethylpropylsulfone, methylphenylsulfone,methylsulfolane, and dimethylsulfolane). These cosolvents may be usedalone or in combination.

The amount of the cosolvent can be varied depending on a variety offactors, including the properties of the cosolvent (solubility and/ordielectric constant), the type of modified pigment, and the desiredperformance of the resulting inkjet ink composition. In particular, theoptional cosolvent may be used in amounts of less than or equal to about40% by weight based on the total weight of the inkjet ink composition,including less than or equal to about 30% and less than or equal toabout 20%. Also, when used, the amount of the optional cosolvent isgreater than or equal to about 2% by weight based on the total weight ofthe inkjet ink composition, including greater than or equal to about 5%and greater than or equal to about 10% by weight.

EXAMPLES Example 1 Preparation of Carbon Blacks

The carbon black was prepared in a pilot plant according to oneembodiment of a multi-stage reactor depicted in FIG. 1. The reactordimensions are outlined in Table 1 below.

TABLE 1 FIG. 1 label Component 10, 11 XB-102R burner with tab can 144.5″ First Stage Transition w/6 tips 16A 5.3″ Spacer Transition 16B 5.3″Second Stage Transition w/4 tips 18 (1) 9″ Entry Reactor Section 18 (2)13.5″ Reactor Sections 18 (2) 18″ Reactor Sections 18 (2) 27″ ReactorSections 18 (3) 36″ Reactor Sections

The process conditions for Samples A-H are outlined in Table 2 below.

TABLE 2 Operating conditions A B C D E F G H Air rate [Nm³/hr] 3099 30993099 3099 3099 3099 3099 3099 Air preheat temp [° C.] 538 538 Overallcombustion [%] 41 44 41 44 44 44 44 41 Primary combustion [%] 120 120120 120 120 120 120 120 Total feedstock rate [kg/hr] 496 445 496 445 445445 445 496 FDS temperature [° C.] 197 197 Ring 1 tip quantity 6 6 6 6 66 6 6 Ring 1 tip size [inch] 0.021 0.018 0.021 0.018 0.021 0.024 0.0200.020 Ring 1 pressure [bar] 45 45 45 53 45 45 54 47 Ring 2 tip quantity4 4 4 4 4 4 4 4 Ring 2 tip size [inch] 0.021 0.018 0.021 0.018 0.0140.014 0.014 0.020 Ring 2 pressure [bar] 60 60 60 64 60 60 53 48 K⁺concentration [ppm] 0 0 0 0 0 0 5 0 Quench location [inch] 32 32 32 3232 32 32 32 Percent feedstock in first location 60 60 60 60 70 80 70 60No. of second injection locations 1 1 1 1 1 1 1 1

The properties of the raw material carbon blacks prepared under theseconditions are outlined in Table 3 below.

TABLE 3 Carbon BET STSA OAN COAN BET-ST Black Sample (m²/g) (m²/g)(mL/100 g) (mL/100 g) (m²/g) OAN/COAN STSA/BET A 210.4 172.5 177.4 133.638 1.33 0.82 B 241.8 182.6 190.2 141.5 59 1.34 0.76 C 196.8 163.5 196.5140.6 33 1.40 0.83 D 248.5 188.5 178.2 130.5 60 1.37 0.76 E 261.3 200.3172.8 128.5 61 1.34 0.77 F 270.6 207.1 173.7 122.0 64 1.42 0.77 G 257.0194.0 178.5 128.5 63 1.39 0.75 H 205.0 169.0 183.0 135.0 36 1.36 0.9

The properties of other high structure carbon blacks that can be madefrom the same apparatus under similar operating conditions are listed inTable 4 below.

TABLE 4 BET STSA OAN COAN carbon black (m²/g) (m²/g) (mL/100 g) (mL/100g) I 155.4 143.2 199.3 136.7 J 180.5 146.5 181.5 124.0 K 162.2 151.4181.7 132.2 L 175.0 155.5 172.7 131.6

Example 2 Oxidation with Ozone

This Example describes the ozonation of carbon black Samples A-G ofExample 1 by using the ozone reactor assembly of FIG. 2 outfitted with aventuri tube.

A carbon black charge from Example 1 (300 g) was combined with water (6L) and this mixture was homogenized with a rotor-stator at 8,000-10,000rpm for 3-5 minutes. The resulting slurry was added to the reservoir ofthe ozone reactor assembly, in which the reservoir pH was maintained at9.0. The recirculation pump was operated at a rate of 70-90 L/min tocirculate the slurry throughout the reactor. Ozone gas (3-5 wt %) wasintroduced to the slurry via an inlet at the venturi tube at a gas flowrate of 6-10 L/min. Ozonation was performed over a 9 h time period at areaction temperature of 30-40° C.

Alternatively, a carbon black charge from Example 1 (300-600 g) wascombined with water (4-7 L) and this mixture was homogenized with arotor-stator at 8,000-10,000 rpm for 3-5 minutes. The resulting slurrywas added to the reservoir of the ozone reactor assembly, in which thereservoir pH was maintained at 9.0. The recirculation pump was operatedat a rate of 70-90 L/min to circulate the slurry throughout the reactor.Ozone gas (2-5 wt %) was introduced to the slurry via an inlet at theventuri tube at a gas flow rate of 6-10 L/min. Ozonation was performedover a 7-9 h time period with the temperature of the reaction being30-40° C.

Example 3 Modification with 4-Aminobenzoic Acid

This Example describes the modification of carbon black samples A-F ofExample 1 with 4-aminobenzoic acid (pABA). While this modification wasperformed on raw material carbon blacks, the same treatment can beperformed on the oxidized carbon black samples of Example 2.

A mixture comprising a carbon black charge (500 g) from Example 1, pABA(50-75 g), and water (1-2 L) was added to a Processall reactor. Thetemperature was raised to 55° C. and sodium nitrite (20%, 150-220 g) wasadded to this mixture over a time period of 20 min. The reaction wasperformed for 1-2 h at 65° C.

Example 4 Modification with EBP

This Example describes the modification of carbon black samples A-F ofExample 1 with2-(4-aminophenyl)-1-hydroxyethylidene-1,1-bisphosphonicacid (EBP). Amixture comprising a carbon black charge (500 g) from Example 1, EBP(50-75 g), and water (1-2 L) was added to a Processall reactor. Thetemperature was raised to 55° C. and sodium nitrite (20%, 150-220 g) wasadded to this mixture over a time period of 20 min. The reaction wasperformed for 1-2 h at 65° C.

Example 5 Preparation of Dispersions

This Example describes the preparation of dispersions using theoxidized/treated carbon black materials of Examples 2-4. Diafiltrationwas performed with a Pall Microza® ultrafiltration membrane (SLP-1053)to a permeate conductivity of less than 150 uS/cm or to a retentateconductivity of less than 1000 uS/cm at 15% dispersion solids. (Forsamples G-O-S and G-O-U, prior to diafiltration, the resultingdispersions were subjected to a heat treatment where the dispersion isheated to a minimum of 75° C. for 2 h with magnetic or overheadstirring). The sample was then diluted to 5% solids and centrifuged on aCarr® Powerfuge® at 13276 RPM with either a 300 or 600 mL/min flow rate.The sample was reconcentrated to 16% solids with a Pall Microza®ultrafiltration membrane (SLP-1053) and sonicated with a Misonix® Labprobe sonicator inside a vessel with a cooled jacket with magneticstirring to a D50 target particle size of 140 nm (for comparison, asecond set of ozone-oxidized carbon black samples were not subjected tothis sonication step). Biocide was added (0.2% (w/w) Proxel®) and thesample was passed through either a 0.3 or 0.5 μm Pall depth filter. Thesample was adjusted to 15% solids by adding water.

Properties of the dispersions prepared from the ozone oxidized carbonblack samples of Example 2 are listed in Table 5 below. “0” indicatesoxidized; “S” indicates sonicated dispersions; “U” indicates unsonicateddispersions; LPC=large particle content.

TABLE 5 mean Dispersion Solids volume D10 D50 D90 D100 ViscosityConductivity LPC >1.0 μm LPC >0.5 μm Sample (wt %) pH [μm] [μm] [μm][μm] [μm] [cPs] [μS/cm] (×10⁶) (×10⁸) A-O-S 14.59 7.65 0.1389 0.08120.1273 0.2120 0.486 4.22 950 1.4  2.8 B-O-S 15.13 7.55 0.1361 0.08140.1292 0.2006 0.409 3.82 1300 1.7  2.4 C-O-S 15.13 7.34 0.1490 0.09120.1377 0.2211 0.486 4.38 1050 2.5  6.9 D-O-S 15.06 7.41 0.1400 0.07940.1355 0.2060 0.409 3.98 1200 0.75  6.7 E-O-S 15.03 7.44 0.1330 0.08740.1278 0.1844 0.409 5.22 1200 1.7  2.2 F-O-S 15.09 7.43 0.1227 0.07350.1129 0.1862 0.409 4.82 1250 1.1  2.2 G-O-S 15.15 9.50 0.1391 0.08840.1314 0.1992 0.409 5.78 900 2.2  7.5 A-O-U 13.85 7.05 0.1619 0.09200.1548 0.2399 0.486 4.40 1400 29 29 B-O-U 15.08 7.09 0.1482 0.09890.1418 0.2048 0.409 4.92 1700 15 20 C-O-U 15.03 7.06 0.1633 0.10370.1556 0.2315 0.486 5.46 1200 13 28 D-O-U 14.97 7.09 0.1591 0.08570.1479 0.2489 0.486 5.28 1560 34 35 E-O-U 14.96 7.10 0.1511 0.09280.1456 0.2159 0.409 6.18 1600 15 14E G-O-U 15.15 9.43 0.1669 0.09530.1515 0.2618 0.578 12.80 800 1.3 30

Properties of the dispersions prepared with the pABA-treated carbonblack of Example 3 are listed in Table 6 below.

TABLE 6 mean Dispersion solids volume D10 D50 D90 D100 LPC >1 μmLPC >0.5 μm Viscosity Cond. Sample (wt %) pH (μm) (μm) (μm) (μm) (μm)(×10⁶) (×10⁸) (cPs) (μS/cm) A-pABA 15.22 9.05 0.1328 0.0844 0.12490.1903 0.409 1.2 7.0 4.90 900 B-pABA 15.17 8.52 0.139 0.0793 0.133 0.2070.409 0.77 4.8 4.50 900 C-pABA 15.10 8.74 0.135 0.0862 0.1278 0.19190.409 0.66 4.9 4.18 825 D-pABA 15.06 9.17 0.1339 0.0784 0.1289 0.19510.409 3.6 7.4 4.12 1000 E-pABA 15.06 9.13 0.1322 0.077 0.1243 0.19690.409 1.2 5.2 6.44 925 F-pABA 14.99 8.72 0.1369 0.0868 0.133 0.19060.409 4.0 5.8 6.56 1125

Example 6 Sedimentation Rates

Sedimentation rates of the dispersions were obtained by the RoughGravity Sedimentation procedure:

-   -   the dispersion was diluted to 3% solids with water;    -   0.100 mL of the dispersion at 3% solids was diluted to 100 mL in        a volumetric flask;    -   the absorbance of this dilute dispersion was measured at 550 nm        using a UV-Vis spectrophotometer (Abs₁);    -   7 mLs of the dispersion at 3% solids was loaded into Beckman        super-centrifuge tubes;    -   the tubes were sealed centrifuged in a Beckman centrifuge at        20700 RPM for 10 minutes (including ramp-up time);    -   the entire supernatant from the sample tubes was collected into        a vial;    -   0.100 mL of the recovered supernatant was diluted to 100 mL in a        volumetric flask; and    -   the absorbance of this dilute dispersion at a wavelength of 550        nm is measured using a UV-Vis spectrophotometer (Abs₂).

The sedimentation rate was determined from the Abs₁ and Abs₂ valuesaccording to the following formula:

% sedimentation=100*((Abs₁−Abs₂)/Abs₁)

Sedimentation rates for certain dispersions of Example 5 are listed inTable 7 below:

TABLE 7 Carbon Black Sample Sedimentation Rate (%) A-O-S 70.2 B-O-S 75.2C-O-S 79.7 D-O-S 66.9 E-O-S 61.8 F-O-S 53.5 A-pABA 68.4 B-pABA 74.9C-pABA 79.6 D-pABA 70.2 E-pABA 59.0 F-pABA 56.4

Example 7 Inkjet Ink Formulations

Inkjet ink formulations were prepared from the dispersions of Example 5,with components in proportions (in pph) as listed in Tables 8 and 9below.

TABLE 8 Formulation A Percent component (w/w) Pigment 4.0 Surfynol 4651.0 Triethyleneglycol 5.0 monobutylether Glycerin 10.0 Water 80.0

TABLE 9 Formulation B Percent component (w/w) Pigment 4.0 Surfynol 4651.0 Trimethylol propane 7.0 Glycerin 7.0 Diethylene glycol 5.0 Water76.0

Example 8 Optical Density

Inkjet Formulations A and B of Example 7 were printed on Xerox 4200 andHPMP paper. An Epson C88+ inkjet printer was used to print Formulation Aand a Canon iP4000 inkjet printer was used to print Formulation B. Theprinting was performed on Best and Normal modes, as listed in Table 10below along with the resulting optical density values. “A” indicatesFormulation A; “B” indicates Formulation B.

TABLE 10 A A A A A B B B B B Total Best Norm Best Norm Average Best NormBest Norm Average average Dispersion X4200 X4200 HPMP HPMP OD X4200X4200 HPMP HPMP OD OD A-O-S 1.40 1.23 1.50 1.40 1.38 1.28 1.12 1.52 1.581.37 1.38 B-O-S 1.39 1.22 1.50 1.39 1.38 1.23 1.09 1.50 1.52 1.33 1.36C-O-S 1.43 1.26 1.54 1.41 1.41 1.31 1.12 1.52 1.53 1.37 1.39 D-O-S 1.401.24 1.52 1.39 1.38 1.27 1.11 1.48 1.48 1.33 1.36 E-O-S 1.45 1.22 1.531.39 1.40 1.31 1.11 1.49 1.53 1.36 1.38 F-O-S 1.39 1.22 1.47 1.38 1.361.26 1.10 1.46 1.49 1.33 1.34 G-O-S 1.30 1.23 1.39 1.38 1.32 1.35 1.111.54 1.45 1.36 1.34 A-O-U 1.48 1.27 1.59 1.43 1.44 1.36 1.14 1.54 1.581.40 1.42 B-O-U 1.49 1.29 1.60 1.45 1.46 1.32 1.14 1.55 1.56 1.39 1.42C-O-U 1.50 1.28 1.60 1.47 1.46 1.36 1.14 1.57 1.61 1.42 1.44 D-O-U 1.441.23 1.54 1.40 1.40 1.29 1.14 1.48 1.49 1.35 1.37 E-O-U 1.46 1.28 1.571.41 1.43 1.33 1.12 1.51 1.52 1.37 1.40 F-O-U 1.43 1.23 1.54 1.40 1.401.30 1.12 1.49 1.48 1.35 1.37 G-O-U 1.47 1.29 1.58 1.40 1.43 1.41 1.151.60 1.53 1.42 1.43 A-pABA 1.17 1.09 1.35 1.22 1.21 1.13 1.05 1.39 1.431.25 1.23 B-pABA 1.15 1.08 1.32 1.20 1.19 1.12 1.04 1.34 1.27 1.19 1.19C-pABA 1.13 1.05 1.35 1.20 1.18 1.12 1.04 1.38 1.28 1.21 1.19 D-pABA1.18 1.09 1.36 1.22 1.21 1.11 1.02 1.34 1.32 1.20 1.20 E-pABA 1.20 1.101.40 1.26 1.24 1.13 1.05 1.35 1.31 1.21 1.22 F-pABA 1.18 1.09 1.35 1.211.21 1.12 1.03 1.35 1.31 1.20 1.20

The use of the terms “a” and “an” and “the” are to be construed to coverboth the singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The terms “comprising,” “having,”“including,” and “containing” are to be construed as open-ended terms(i.e., meaning “including, but not limited to,”) unless otherwise noted.Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention.

1-51. (canceled)
 52. A dispersion comprising a carbon black having thefollowing properties: OAN≧170 mL/100 g; STSA ranging from 160 to 220m²/g; and BET surface area ranging from 190 to 275 m²/g.
 53. Thedispersion of claim 52, wherein the carbon black is an oxidized carbonblack.
 54. The dispersion of claim 53, wherein the oxidized carbon blackhas a surface comprising at least one group selected from phenols,lactones, carbonyls, carboxyls, anhydrides, ethers, and quinones. 55.The dispersion of claim 53, wherein the carbon black is a modifiedcarbon black.
 56. The dispersion of claim 55, wherein the carbon blackis modified with at least one organic group.
 57. The dispersion of claim56, wherein the at least one organic group comprises the formula—[R(A)]-, wherein: R is attached to the carbon black and is selectedfrom arylene, heteroarylene, and alkylene, and A is selected fromcarboxylic acids, sulfonic acids, phosphonic acids, hydroxyls, amines,and esters, amides, and salts thereof.
 58. The carbon black of claim 57,wherein R comprises the formula R′—Sp, wherein R′ is selected fromarylene, heteroarylene, and alkylene, and Sp is a spacer selected from—CO₂—, —P₂C—, —CO—, —OSO₂—, —SO₃—, —SO₂—, —SO₂C₂H₄—O—, —SO₂C₂H₄S—,—SO₂C₂H₄NR″—, —O—, —S—, —NR″—, —NR″CO—, —CONR″—, —NR″CO₂—, —O₂CNR″—,—NR″CONR″—, —N(COR″)CO—, —CON(COR″)—, —NR″COCH(CH₂CO₂R″)— and cyclicimides therefrom, —NR″COCH₂CH(CO₂R″)— and cyclic imides therefrom,—CH(CH₂CO₂R″)CONR″— and cyclic imides therefrom, —CH(CO₂R″)CH₂CONR″ andcyclic imides therefrom, sulfonamide groups, arylene groups, alkylenegroups, and R″, which can be the same or different, is selected fromhydrogen, substituted and unsubstituted C₅-C₂₀ aryl groups, andsubstituted and unsubstituted C₁-C₆ alkyl groups.
 59. The carbon blackof claim 57, wherein R comprises the formula R′—Sp, wherein R′ isselected from arylene, heteroarylene, and alkylene, and Sp is a spacerderived from a compound having a reactive group selected from acarboxylic acid or ester, an acid chloride, a sulfonyl chloride, an acylazide, an isocyanate, a ketone, an aldehyde, an anhydride, an amide, animide, an imine, an α,β-unsaturated ketone, aldehyde, or sulfone, analkyl halide, an epoxide, an alkyl sulfonate or sulfate such as a(2-sulfatoethyl)-sulfone group, an amine, a hydrazine, an alcohol, athiol, a hydrazide, an oxime, a triazene, a carbanion, an aromaticcompound, and salts and derivatives thereof, or any combination thereof.60. The carbon black of claim 57, wherein R comprises the formula R′—Sp,wherein R′ is selected from arylene, heteroarylene, and alkylene, and Spis a spacer derived from a compound selected from 4-aminobenzyl amine,3-aminobenzyl amine, 2-aminobenzyl amine, 2-aminophenyl ethylamine,4-aminophenyl-(2-sulfatoethyl)-sulphone, p-aminobenzoic acid,4-aminophthalic acid, and 5-aminobenzene-1,2,3-tricarboxylic acid. 61.The dispersion of claim 52, wherein the carbon black has a mean volumeranging from 0.1 to 0.18 μm.
 62. The dispersion of claim 52, wherein thecarbon black has a D10 ranging from 0.05 to 0.1 μm.
 63. The dispersionof claim 52, wherein the carbon black has a D10 ranging from 0.06 to 0.1μm.
 64. The dispersion of claim 52, wherein the carbon black has a D10ranging from 0.07 to 0.1 μm.
 65. The dispersion of claim 52, wherein thecarbon black has a D50 ranging from 0.1 to 0.16 μm.
 66. The dispersionof claim 52, wherein the carbon black has a D90 ranging from 0.18 to0.25 μm.
 67. The dispersion of claim 52, wherein the carbon black has aD90 ranging from 0.15 to 0.24 μm.
 68. The dispersion of claim 52,wherein the carbon black has a D90 ranging from 0.18 to 0.24 μm.
 69. Thedispersion of claim 52, wherein the carbon black has a COAN of at least120 m²/g.
 70. The dispersion of claim 52, wherein the dispersion isaqueous.
 71. An inkjet ink composition comprising the dispersion ofclaim
 52. 72. A carbon black having the following properties: OAN≧170mL/100 g; BET surface area ≧150 m²/g; and COAN of at least 130 m²/g.